Hi Markus,
Thanks for your reply. I've been trying to undestand the explanation of 90.1-2013 User's Manual, page G-35. That's why I've decided to ask about, because I was not sure for which cases this System 13 is to be applied and it was mentioned there in relation to the peak load value of my project. Most probably within the explanation I've taken "primary" for "proposed" Thanks again and I'll stick to System 11.